GHC-2.10's "overlapping pattern matches"-warnings are sometimes quite puzzling:
------------------------
module Foo where
bar "-" = 1
bar ('-':xs) = 2
bar _ = 3
baz ('-':[]) = 1
baz ('-':xs) = 2
baz _ = 3
------------------------
Transcript:
panne@liesl:/tmp > ghc -c Foo.hs
Foo.hs:3:
Warning: Pattern match(es) are overlapped
in the definition of function `bar'
`('-' : xs) = ...'
ghc: module version changed to 1; reason: no old .hi file
Why is there a warning for bar but none for baz?
Apart from this buglet, the new warnings are much more informative.
BTW, what do the "discarding polymorphic case"-warnings mean and
under what circumstances do they occur? I think this has been asked
before, but I could not find the answer in my mail folders...
--
Sven Panne Tel.: +49/89/2178-2235
LMU, Institut fuer Informatik FAX : +49/89/2178-2211
LFE Programmier- und Modellierungssprachen Oettingenstr. 67
mailto:[EMAIL PROTECTED] D-80538 Muenchen
http://www.pms.informatik.uni-muenchen.de/mitarbeiter/panne
